In the related art, an image forming apparatus such as a multifunction peripheral (MFP) reduces the level of operating sound by decreasing, for example, a transport speed at which a sheet on which an image is formed, is transported during operation. The image forming apparatus measures the level of sound in the surrounding area of the image forming apparatus and determines the presence or the absence of a person in the surrounding area with the measured level of sound. Then, the image forming apparatus changes the transport speed according to the determination result.
However, since such an image forming apparatus determines the presence or the absence of a person in the surrounding area with the level of sound, the image forming apparatus may determine the absence even though, in actuality, a person exists quietly in the surrounding area of the image forming apparatus. Thus, the method of detecting a person in the surrounding area of the image forming apparatus may not be accurate.